The effects of delta9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on hydroxylation of estradiol and testosterone in rat liver microsomes were investigated. Acute and chronic treatment of male and female rats with either cannabinoid, 2 or 10 mg/kg, significantly elevated steroid hydroxylase activity. Acute administration of THC or CBD, 10 mg/kg, evoked no detectable changes in cytochrome P-450 levels, but a significant decrease in those of cytochrome b5. Chronic administration of THC or CBD, 2 mg/kg, decreased levels of cytochrome P-450, whereas cytochrome b5 levels appeared normal. Acute doses of THC or CBD at 10 mg/kg significantly depressed testosterone formation in testis microsomes. Chronic THC, 2...

Cannabidiol (CBD) is a major, biologically active, but psycho-inactive component of cannabis. In this cell culture-based report, CBD is shown to displace the agonist, [3H]8-OHDPAT from the cloned human 5-HT1a receptor in a concentration-dependent manner. In contrast, the major psychoactive component of cannabis, tetrahydrocannabinol (THC) does not displace agonist from the receptor in the same micromolar concentration range. In signal transduction studies, CBD acts as an agonist at the human 5-HT1a receptor as demonstrated in two related approaches. First, CBD increases [35S]GTPcS binding in this G protein coupled receptor system, as does the known agonist serotonin. Second, in this GPCR system, that is negatively...

To present a summary of current scientific evidence about the cannabinoid, cannabidiol (CBD) with regard to its relevance to epilepsy and other selected neuropsychiatric disorders. We summarize the presentations from a conference in which invited participants reviewed relevant aspects of the physiology, mechanisms of action, pharmacology, and data from studies with animal models and human subjects. Cannabis has been used to treat disease since ancient times. D9 -Tetrahydrocannabinol (D9 -THC) is the major psychoactive ingredient and CBD is the major nonpsychoactive ingredient in cannabis. Cannabis and D9 -THC are anticonvulsant in most animal models but can be proconvulsant in some healthy animals. The psychotropic...

Many constituents of cannabis exhibit beneficial anti-inflammatory properties, such as 9-tetrahydrocannabinol (THC) in marijuana and gamma-linolenic acid (GLA) in hemp seed oil. The effects of these cannabis constituents on eicosanoid metabolism is reviewed. THC and GLA modulate the arachidonic acid cascade, inhibiting the production of series 2 prostaglandins and series 4 leukotrienes. Cannabinoid receptor- as well as non-receptor-mediated signal transduction pathways appear to be involved. It is proposed that THC acts as a selective cyclooxygenase-2 (COX-2) inhibitor.

D9 -Tetrahydrocannabinol (THC) is the primary cannabinoid of marijuana and has been shown to either potentiate or inhibit tumor growth, depending on the type of cancer and its pathogenesis. Little is known about the activity of cannabinoids like THC on epidermal growth factor receptor-overexpressing lung cancers, which are often highly aggressive and resistant to chemotherapy. In this study, we characterized the effects of THC on the EGFinduced growth and metastasis of human non-small cell lung cancer using the cell lines A549 and SW-1573 as in vitro models. We found that these cells express the cannabinoid receptors CB1 and CB2, known targets for THC action,...

Cyclooxygenase enzymes (COX-1 and COX-2) catalyse the production of prostaglandins from arachidonic acid. Prostaglandins are important mediators in the inflammatory process and their production can be reduced by COX-inhibitors. Endocannabinoids, endogenous analogues of the plant derived cannabinoids, occur normally in the human body. The Endocannabinoids are structurally similar to arachidonic acid and have been suggested to interfere with the inflammatory process. They have also been shown to inhibit cancer cell proliferation. Antiinflammatory effects of cannabinoids and endocannabinoids have been observed, however the mode of action is not yet clarified. Anti-inflammatory activity (i.e., inhibition of COX-2) is proposed to play an important role in the...

Cannabis is the most commonly used illicit substance among pregnant women. Human epidemiological and animal studies have found that prenatal cannabis exposure influences brain development and can have long-lasting impacts on cognitive functions. Exploration of the therapeutic potential of cannabis-based medicines and synthetic cannabinoid compounds has given us much insight into the physiological roles of endogenous ligands (endocannabinoids) and their receptors. In this article, we examine human longitudinal cohort studies that document the longterm influence of prenatal exposure to cannabis, followed by an overview of the molecular composition of the endocannabinoid system and the temporal and spatial changes in their expression during brain development....

In glaucoma, the increased release of glutamate is the major cause of retinal ganglion cell death. Cannabinoids have been demonstrated to protect neuron cultures from glutamate-induced death. In this study, we test the hypothesis that glutamate causes apoptosis of retinal neurons via the excessive formation of peroxynitrite, and that the neuroprotective effect of the psychotropic 9-tetrahydroxycannabinol (THC) or nonpsychotropic cannabidiol (CBD) is via the attenuation of this formation. Excitotoxicity of the retina was induced by intravitreal injection of N-methyl-Daspartate (NMDA) in rats, which also received 4-hydroxy-2,2,6,6-tetramethylpiperidine-n-oxyl (TEMPOL, a superoxide dismutase-mimetic), N--nitro-L-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor), THC, or CBD. Retinal neuron...

Abstract Cannabis extracts and synthetic cannabinoids are still widely considered illegal substances. Preclinical and clinical studies have suggested that they may result useful to treat diverse diseases, including those related with acute or chronic pain. The discovery of cannabinoid receptors, their endogenous ligands, and the machinery for the synthesis, transport, and degradation of these retrograde messengers, has equipped us with neurochemical tools for novel drug design. Agonist-activated cannabinoid receptors, modulate nociceptive thresholds, inhibit release of pro-inflammatory molecules, and display synergistic effects with other systems that influence analgesia, especially the endogenous opioid system. Cannabinoid receptor agonists have shown therapeutic value against inflammatory and neuropathic pains,...

Various psychiatric disorders such as major depression are associated with abnormalities in emotional processing. Evidence indicating involvement of the endocannabinoid system in emotional processing, and thus potentially in related abnormalities, is increasing. In the present study, we examined the role of the endocannabinoid system in processing of stimuli with a positive and negative emotional content in healthy volunteers. A pharmacological functional magnetic resonance imaging (fMRI) study was conducted with a placebo-controlled, cross-over design, investigating effects of the endocannabinoid agonist Δ9-tetrahydrocannabinol (THC) on brain function related to emotional processing in 11 healthy subjects. Performance and brain activity during matching of stimuli with a negative (‘fearful...